HIV+ patients have difficulties in cognitive realms consistent with dysfunction of the fronto-striatal network. This study aims to characterize atrophy in a group of asymptomatic HIV+ patients using volumetric MRI techniques, thereby investigating the effects of the virus on brain structure before the illness progresses to AIDS. In addition, this study aims to enhance the understanding of brain functioning after HIV infection by using fMRI to investigate brain activity during a reasoning task, a cognitive realm that appears impacted by the virus. Importantly, this proposal will analyze the data from both the structural and functional MRIs in conjunction with one another, thereby addressing how structure and function are impacted after infection with HIV. It also aims to explore how cognitive deficits as measured by standard neuropsychological testing procedures correlate with brain structure and function. These studies will increase scientific understanding of the impact of HIV on brain functioning in asymptomatic patients. Increasing knowledge of how functional and structural changes interact in HIV has implications for both understanding the course of HIV cognitive decline, and for identifying an opportunity for early cognitive intervention. [unreadable] [unreadable]